1. Field of the Invention
The present invention relates to a laser induced thermal imaging apparatus and laser induced thermal imaging method, and more particularly, to a laser induced thermal imaging apparatus and laser induced thermal imaging method for performing a process of laminating a donor film and an acceptor substrate by using magnetic force.
2. Discussion of Related Art
An organic light emitting device is a device that has a light emitting layer located between a first electrode and a second electrode. The organic light emitting device emits light by combining holes and electrons at the light emitting layer when a voltage is applied between the electrodes. Hereinafter, the prior art and the present invention will be described in reference to the laser induced thermal imaging apparatus used for fabricating an organic light emitting device, however, the present invention is not limited thereto.
The laser induced thermal imaging method irradiates a laser on a donor substrate including a base substrate, a light-to-heat conversion layer and a transfer layer (or imaging layer), and converts the laser passing through the base substrate into heat in the light-to-heat conversion layer, so that the light-to-heat conversion layer is deformed and expanded to deform and expand the neighboring transfer layer. This way, the transfer layer is adhered to the acceptor substrate, such that the transfer layer can be transferred to the acceptor substrate.
When performing the laser induced thermal imaging method, the inside of a chamber in which the imaging is done should be in a vacuum state, in order to comply with a deposition process when forming the light emitting device. However, when performing the laser induced thermal imaging in the vacuum state according to the prior art, there has been a problem that the imaging from the imaging layer is not carried out well due to a foreign substance (or impurities) or a space (void or gap) generated between the donor substrate and the acceptor substrate. Therefore, in the laser induced thermal imaging method, a method for laminating the donor substrate and the acceptor substrate is important, and various schemes for solving the problem with the space or impurities have been contemplated.
FIG. 1 is a partial cross sectional view of a laser induced thermal imaging apparatus according to the prior art for overcoming the above problems. According to FIG. 1, a laser induced thermal imaging apparatus 10 includes a substrate stage 12 positioned inside a chamber 11 and a laser oscillator 13 positioned at an upper part of the chamber 11.
The substrate stage 12 is a stage for placing an acceptor substrate 14 and a donor film 15, which are introduced into the chamber 11.
In this case, in order to laminate an acceptor substrate 14 and the donor film 15 without generating the foreign substance or the space between the acceptor substrate 14 and the donor film 15, the inside of the chamber 11 in which the laser induced thermal imaging is performed, is not to be maintained in the vacuum state but to be sucked by a vacuum pump P by connecting a hose 16 to the lower part of the substrate stage 12, adhering the acceptor substrate 14 and the donor film 15. However, in such a prior art, since the generation of the foreign substance 1 and the void between the acceptor substrate 14 and the donor film 15 cannot be completely prevented and furthermore, the vacuum state inside the chamber 11 cannot be maintained, it has been known to have an adverse effect on reliability and duration of a product.